f = open('data.txt', 'r')

</source><br>The '''open()''' function takes two string arguments: a path to a file, and a mode option (to ask for reading, writing, appending, etc). The ''open()'' function will return a file object to us, this file object will allow us to read the lines inside the file.<br><br>

f.read() # read all lines and stores in a string

f.readlines() # read all lines and stores in a list